My users do not have ~/.inputrc files and the system-wide /etc/inputrc file, unchanged default for Ubuntu 11.10, does not have any history-size defined. Nor does the readline man page show any default for it, except implying (0) or unlimited.

Yet every time I login my prompt shows that I have only 5000, despite having added many more unique command lines during my last session, or saving with history -w without having logged off.

Where is this limitation set and how can I override it?

My prompt and other possibly interesting settings from ~/.bashrc or files it sources: